How do I wipe stdout?

Today I used Terminal (invoked from Mac OS X 10.4.11) to view some data that is secured by a password.

After exiting Terminal, it occurred to me that a vestige of the data displayed on my screen might reside in memory or in disk file ... the actual file used for stdout, for example.

Do I need to take precautions to prevent the the temporary perusal of sensitive data from creating an image that hangs around after I exit, or is Unix pretty good about wiping the slate clean when I exit?

Use ^D or whatever to get rid of the terminal. So nobody can see it.

After that, no vestige will remain. stdout is not a file on disk or in memory. There is a file /dev/stdout but nothing "stays" in there. You do not need to take any more precautions, other than obviously safeguarding the actual file that holds the sensitive data.